1. Field of the Invention
The present invention relates to a novel electrically conductive polymer, a sensor having an electrode coated with the electrically conductive polymer, and a method for detecting a target molecule using the sensor.
2. Description of the Related Art
There have been many studies on the development of biomolecule detecting sensors based on the electrochemical principles. One advantage of using the electrochemical principles lies in that sensors can be miniaturized. Accordingly, there have been great advances in research on electrochemical sensors, such as ionic sensors, gas sensors, biosensors, etc. In the fields of genomics and proteomics, it is very important to monitor information on the hybridization of DNA, among other biological molecules, and to monitor conformational changes of proteins. To this end, there have been developed sensors using organic materials, such as intercalators having electrochemical activities, and using electrically conductive polymers. In particular, intercalator-based sensors are ready to be released on the market as a result of extensive research thereon.
In conductive polymer sensors, only a few representative monomers capable of being polymerized on electrodes are available, and it is difficult to control the physical properties of polymers. As a result, research thereon has been relatively slow. Representative materials for conductive polymer sensors include pyrroles, thiophenes, anilines, and the like. However, because of a limitation that anilines are effective only in acidic conditions, pyrroles and thiophenes have been the main focus of research.
However, pyrroles cannot be used for a long duration due to their small redox potential (U.S. Pat. No. 6,201,086). Thiophenes have a higher redox potential but are more hydrophobic than pyrroles, so they are unsuitable for biomolecule dispersion systems in water (Bauerle P. and Emge A., Adv. Materi., 3:324 (1998)).